Oregon 22-455 Heavy-Duty Professional Magnum Gatorline Square String Trimmer Line .155-Inch Diameter 1-Pound Donut Outer layer prevents welding High strength inner core resists breaking Long life, excellent strength .155-inch diameter 1-pound donut containing 84-feet High resistance to abrasion and breakage. Flexible core provides outstanding durability. Less engine drag, vibration, and noise. Engineered to resist welding up to 498 F. Outer layer prevents welding. User friendly donut  fewer tangles. High strength inner core resists breaking. Long-life, excellent strength. Fits all standard trimmer heads. User-friendly donut, limits tangles. Fits all standard trimmer heads. Effective in all cutting conditions.